Distributing valve for rock drills



- 1614 969 1927' F. w. RUDLIN DISTRIBUTING VALVE FOR ROCK DRILLS Filed Deg. 17, 1925 G c PLd INVENTOR flea rickJ/K 14:11:):

Patented Jan. 18, 1927.

UNITED-STATES PATENT OFFICE.

FREDERICK W. RUDLIN, 0F PHILLIPSBURG, NEW JERSEY, ASSIGNOR TO INGERSOLL- RAND GOMPANY,'OF JERSEY CITY, NEW JERSEY, A QORPOR-ATOIN OF NEW'JERSEY.

DISTRIBUTING VALVE FOR ROCK DRILLS.

Application filed December This invention-relates to rock drills, but more particularly to distributing valves for rock drills of the fluid actuated type.

The objects of this invention are to minimize the air consumption of drills of this type, to insure a quick and positive valve action, and to hold the length of the inlet passages leading from the valve chambers to the ends of the cylinder to a minimum.

Other objects will be in part obvious and in part pointed out hereinafter. V

The invention consists of the combinations of elements, features of construction, and arrangement of parts having the general mode of operation substantially as hereinafter described and more particularly pointed out in the appended claims and illustrated in the accompanying drawings, in which-- i Figure 1 is an elevation in section of so much of a rock drill as will serve to illustrate the invention, showing the valves in position for admitting air to the rear end of thecylinder to drive the piston forwarch ly. and

Figure 2 is a view similar to Figure l showing the valves in position to admit pressure fluid to the front end of the cylinder for returning the piston.

Referring to the drawings, the invention is shown embodied in a rock drill having a cylinder A provided in this instance with a free exhaust port B, preferably arranged intermediate the ends of the cylinder. A hammer piston C is adapted to reciprocate in the cylinder A and. carries a forwardly extending nose D slidable through a front cylinder washer E which also serves as a closure for the front end of the cylinder A. A closure for the rear end of the cylinder A is provided in the form of a back head F.

In the present instance a valve chest G shown as being formed integrallywith the cylinder A and has a longitudinal inlet chamber H which is in constant communication with a source of live pressure fluid supply through a connection J and a passage K. At the ends of the inlet chamber H are formed valve chambers L and L having reduced portions 0 and P respectively and outer enlarged actuating and holding chambers Q, and B respectively. The chamber Q in this instance is sealed at its outer end by the back head F formed to extend across 17, 1925. Serial No. 76,040.

the end of the chamber Q, and the chamber R is preferably sealed by a plug S screw threaded into the end of said chamber. A convenient means for holding the plug S against accidentalv removal is shown in the form of an expansible spring ring T seated in an annular groove U rearwardly of the plug S. 7

Within the chamber L is a reciprocable valve V having a reduced. portion W extendingslidably into the chamber 6 and an end head or flange X which extends into the chamber Q. An inner face Y of the valve V constitutes an actuating face against which live pressure fluid may constantly act for opening the valve. An outer face Z of the flange X serves as an actuating and holding face against which pressure fluid may act for closing the valve and formomentarily holding the valve in closed position. In like manner, a valve b-is arranged in the chamberL and has a reduced portion 0 extending into the chamber P and a flange or head (Z extendinginto the chamber R. The valve Z), like the valve V is likewise provided with an inner actuating face Y against which pressure fluid may constantly act for opening the valve. The flange (Z also has an actuating and holding face Z against which pressure fluid may act intermittently for closing the valve and for holding it in closed position.

Disposed in the ends of the chamber H are cylindrical hollow bushings e which serve as seats for the valves V and b. The bushings 6 may be secured in position either by being press fitted as indicated in the drawings, or, by any other suitable and convenient means.

Leading from the front and rear ends of the cylinder A to corresponding ends of the chamber H are inlet passages f and g. The inlet passages f and g are in this instance controlled by the valves Z) and V respectively and preferably surround the small ends of thevalves, so that when the valves open a full supplyof pressure fluid will-be quickly supplied to the ends of the cylinder.

Leading f'romthe inlet passage g t-othe actuating and holding chamber R is a pas sage k. A similar passage j leads from the inlet passage f to the actuating and holding chamber As will be observed, the passages h and j are crossed so thatwh en one or the other of the inlet passages a and f are uncovered by their respective valves, a portion of the pressure fluid passing therethrough will flow to one or the other of the actuating and holding chambers Q, and R for holding one or the other of the valves closed, depending upon the position of the piston C.

The operation of the drill is as follows: lVith the piston C in the position indicated in Figure 1, the exhaust port B will be uncovered so that the front end of the cylinder A will be open to the atmosphere. Pressure fluid then admitted into the chamber H may momentarily throw both valves open. I-Iow' ever, with the rearward end of the cylinder closed, a portion of the pressure fluid ad mitted rearwardly of the piston will pass through the passage it into the chamber R and close the valve 7). The pressure fluid thus admitted to the chamber R will hold the valve 6 closed until the piston C has overrun the exhaust port B sufliciently to establish communication between the rearward end of the cylinder and the atmos phere. After the piston C has closed the exhaust port B, the atmospheric air entrapped in the front end of the cylinder will be compressed and passing through the inlet passage f and through. the passage into the chamber Q will act against the actuating face Z of the valve V and move said valve into its closed position. lVhen the piston C reaches its forward limiting position, or in other words, when it delivers its blow against the drill steel, the rearward end of the cylinder will. be opened to the atmosphere, so that the pressure fluid in the chamber R will be exhausted therefrom, together with the pressure fluid utilized for impelling the piston forwardly. lVith the chamber R open to the atmosphere, the live pressure fluid acting against the actuating face Y of the valve 6 will open the valve to admit pressure fluid to the front end of the cylinder. A portion of the pressure fluid thus admitted through the passage 7 will flow through the passage j and into the chamber Q, to act against the face Z of the valve V to hold said valve closed until the front end of the cylinder is again opened to the atmosphere, when the position of the valves will again be reversed.

I claim:

1. In a fluid actuated'roclt drill, the com bination of a cylinder having a free exhaust port, a reciprocatory piston in the cylnider controlling said exhaust port, a valve chest having an inlet chamber, valve chambers at the ends of said inlet chamber and coaxial therewith, inlet passages leading from the valve chambers to the ends of the cylinder,

and differential valves reciprocable in the chambers for controlling the admission of pressure fluid through the inlet passages to the ends of the cylinder, said valves being constantly exposed at their small ends to live pressure fluid in the inlet chamber for opening said valves and intermittently exposed to live pressure fluid at their large ends for holding said valves in closed position.

2. In a fluid actuated rock drill, the combination of a cylinder having a free exhaust port, a reciprocatory piston in the cylinder controlling said exhaust port, a valve chest having an inlet chamber, valve chambers at the ends of said inlet chamber and coaxial therewith, inlet passages leading from the valve chambers to the ends of the cylinder, and differential valves reciprocable in the chambers for controlling the admission of pressure fluid through the inlet passages to the ends of the cylinder, said valves having inner end actuating faces constantly exposed to live pressure fluid in the inlet chamber for opening the valves and outer end actuating and holding faces intermittently exposed to compressed atmospheric air for closing the valves and intermittently exposed to live pressure fluid for holding the valves in closed position.

3. In a fluid actuated rock drill, the combination of a cylinder having a free exhaust port, a reciprocatory piston in the cylinder controlling said exhaust port, a valve chest having an inlet chamber, valve chambers at the ends of said inlet chamber and coaxial with respect to each other, inlet passages leading from the chambers to the ends of the cylinder, differential valves reciprocable in the chambers for controlling the admission of pressure fluid to the ends of the cylinder, said valves having small inner actuating faces constantly exposed to live pressure fluid in the inlet chamber for opening the valves, and large outer actuating and holding faces intermittently exposed to compressed atmos pheric air generated by the piston for throwing the valves and intermittently exposed, to live pressure fluid for holding the valves in closed position, and crossed passages leading from the ends of the cylinder to the outer ends of the valve chambers for the admission of compressed atmospheric air and live pressure fluid to said chambers for crosing the valves and for holding said valves in closed position. 7

In testimony whereof I have signed this specification.

FREDERICK W. nUDLrr 

